20 Things You Somehow Missed In Shutter Island

20. Chuck's Inexperience With Weapons

There's a tell incredibly early on that Teddy Daniels' new "partner" Chuck Aule (Mark Ruffalo) isn't the U.S. Marshal that he is presented to us as.

When the pair first arrive at Ashecliffe Hospital on Shutter Island, Deputy Warden McPherson (John Carroll Lynch) asks them to surrender their weapons, at which point Aule awkwardly fumbles with his gun holster, before handing over both his gun and the holster to an exasperated McPherson.

It's tough to picture a veteran cop ever handling a gun so clumsily, so it's a major upfront clue that Chuck isn't who he says he is. And of course, it's revealed later in the story that he's actually Teddy's doctor, Dr. Lester Sheehan.